270 BULLETIN 82, UNITED STATES NATIONAL MUSEUM. 



terminal portion of the pinnule this process becomes slightly longer and moves 

 proximally, so that its proximal border is continuous with the proximal border of 

 the main portion of the plate; the notch in the outer border also becomes more 

 constant and more prominent. In the axis parallel with the longitudinal axis of 

 of the pinnule the plates are slightly convex exteriorly ; in the axis at right angles 

 to this they are rather strongly curved. 



In other specimens this adambulacral armament is seen in various stages of 

 degeneration, and apparently may be entirely absent. 



The tentacles contain a conspicuous continuous band of fine interlaced spicules, 

 which runs along the outer side nearly to the tip. 



Anthometra adriani. — The lateral perisome of the pinnules is completely in- 

 closed in a continuous series of plates, the distal edges of which overlap the proximal 

 borders of those succeeding; these plates are about as high as broad at the base, 

 becoming higher distally, coarse in texture, with unfinished edges; the proximal 

 border is more or less straight ; the distal is usually in the outer half or two-thirds 

 strongly convex; the middle half of the outer edge is abruptly produced in the 

 form of a long process, which at first is not much longer than broad at the base, 

 with the two outer corners broadlj' rounded, the proximal and distal sides nearly 

 parallel and convex and lying in a plane parallel with the longitudinal axis of the 

 pinnule, but which soon elongates, so that it is about as long as the major basal 

 portion of the plate, moves somewhat nearer the proximal border, and becomes 

 twisted, so that its proximal border is considerably nearer the midline of the pin- 

 nule than the distal ; when the lappets are closed down these plates completely cover 

 the ambulacral groove interlocking exactly like the fingers on the two hands. 



There are no spicules in the tentacles. 



Florometra mari/p. — In the outer portion of each ambulacral lappet is a short 

 rod, usually straight, slightly roughened at the ends, sometimes slightly bent. This 

 rod is often reduced to a mere spicule. 



There are no deposits in the tentacles. 



Florometra laodlce (fig. 770, p. 362).^Each ambulacral lappet contains a long, 

 conspicuous stout rod roughened at each end, especially the outer, or with the 

 ends slightly expanded and pierced with numerous small holes, and slightly bent 

 just before the middle; sometimes these rods are much reduced. 



There are no deposits in the tentacles. 



Florometra aspemma, (figs. 769, 771, p. 362). — In a specimen from Bering Sea 

 each ambulacral lappet contains a long and very stout rod, straight or slightly 

 curved or bent, of which the inner end is slightly irregular and the outer third is 

 thickly beset with short spines, or, more rarely, expanded and perforated with a 

 few holes. 



There are no deposits in the tentacles. 



In a specimen from Monterey Bay, California, each amlnilacral lappet contains 

 a long and prominent rod, roughened at each end, especially at the outer, very 

 rarely forked, and evenly and rather strongly curved. 



There are no spicules in the tentacles. 



